Guest post by David Middleton
From the Department of All Things Ironic…
Solar panels, while they mitigate the effects of global warming by replacing fossil fuels, can add heat in the locations where they are installed, reports a team of University of Arizona researchers.
At first blush, the experimental results, published Thursday in Nature Science Reports, seem to contradict computer simulations that said solar photovoltaic arrays, by intercepting some of the sun’s warming rays and converting them into electricity, would have a cooling effect.
The UA researchers measured the heat-island effect of a solar array at the UA Tech Park at Rita Road and Interstate 10. They found that its overnight temperatures were about five to seven degrees (Fahrenheit) warmer than a nearby plot of undisturbed desert.
Additional experiments are being conducted to determine the potential effect of the measured heating on nearby communities and the overall environment.
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Following the Standard AGW Scientific Method, the observations are consistent with the model, despite being contradictory…
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Results from the team of current and former UA researchers, which included Alex Cronin, Rebecca Minor, Nathan Allen, Adria Brooks and Mitchell Pavao-Zuckerman, are not inconsistent with published computer simulations, said a Colorado atmospheric scientist.
Aixue Hu, research scientist at the National Center for Atmospheric Research, published conclusions from a computer model last year in Nature Climate Change.
Hu found that installations of vast arrays of panels in desert areas would produce a cooling effect of about 3.5 degrees Fahrenheit.
Contacted by phone Thursday, Hu said his study was predicated on highly efficient PV panels that would convert 30 percent of the sun’s energy into electricity. The panels in the UA study had an efficiency of about 20 percent. Hu said his model might produce some slight heating at that efficiency.
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The Nature Science Report found that the Photocoltaic Heat Island (PVHI) effect was actually quite significant. A 1 MW PV plant routinely caused 3–4 °C of PVHI.
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The PVHI effect caused ambient temperature to regularly approach or be in excess of 4 °C warmer than the natural desert in the evenings, essentially doubling the temperature increase due to UHI measured here. This more significant warming under the PVHI than the UHI may be due to heat trapping of re-radiated sensible heat flux under PV arrays at night. Daytime differences from the natural ecosystem were similar between the PV installation and urban parking lot areas, with the exception of the Spring and Summer months, when the PVHI effect was significantly greater than UHI in the day. During these warm seasons, average midnight temperatures were 25.5 + 0.5 °C in the PV installation and 23.2 + 0.5 °C in the parking lot, while the nearby desert ecosystem was only 21.4 + 0.5 °C.
The results presented here demonstrate that the PVHI effect is real and can significantly increase temperatures over PV power plant installations relative to nearby wildlands.
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How many MW of solar PV have been installed in the past 8 years? How much total PVHI has this yielded? Will this have any effect on our government’s mindless obsession with solar power?
The alarmists should be pleased. If they now relocate some weather stations to solar roof tops they may get the warming they crave.
I thought the science was settled. /sarc.
Can anyone tell me if they’ve EVER claimed ANYTHING to be inconsistent with their models? But wait! Silly question. Everything is consistent because they made sure to cover all the bases. Nothing can prove them wrong. Am I right? Do I get a gold star? I know a grant is out of the question.
That gives me great confidence in models of chaotic nonlinear systems for sure.
The biggest drain on the electric grid is heating water . To heat 1 litre of water with a 3.6 kwh element to 70 C ,it takes about 1.4 min’s . Here in Australia most homes have a 250 litre hot water unit, Using those calculations it would take about 6 hours to heat to 70 C. So don’t you think the first step in reducing greenhouse gas emissions from electricity generation would be to put solar hot water units on every house roof ?
So wind and solar generation should only be incorporated into new or existing structures. Do not carpet the natural ecosystem with them.
1) Not enough
2) Most buildings are in the wrong places. IE (Not in deserts)
So delicious you couldnspread it on your morning toast.
Maybe the reason that there isn’t much bird crap on solar panels is that they learn to avoid them. On ‘pane’ of death by frying.
jimmy, +1 ( I noticed the pigeon on the picture left his opinion)
Only the solar CSP, with mirrors, could have that effect, not solar panels (and they solved the bird frying issue)
Griff,
Sill lying I see. They only stopped frying birds in stand-by mode. When in production mode the solar power is still concentrated, so any birds that fly near the tower will still be fried.
Did you check your sense of humor at the door?
I noticed dinner plate sized white smear marks on my solar panels and dismissed birds because of the size but then saw four Pelicans fly overhead and with astonishing accuracy one of them proceeded to show me what he thought of my solar panels .
Any weather stations near these solar fields? If so, discard their information/data.
So in order to stop global warming, they install solar panels that actually produce a heating effect more noticeable than CO2. It’s irony, all right.
Ideal location for temperature measurement stations then, as the warming would then justify more panels, and so on and on.
Photocoltaic Heat Island -> Photovoltaic Heat Island
Someone surely should have had some clue about this….just sayin’ – is it possible they did, but just didn’t care?
One more thing that many don’t get is that in case the PV solar panel doesn’t source any electrical load it has to convert to heat ALL the efficiently captured light (it’s just the 1st law of thermodynamic).
Any hyper-efficient PV solar panel left unloaded heats up the environment around better than the darkest asphalt.
Have a great day.
Massimo
Massimo, I think you have that wrong!
An unload PV panel (ie disconnected) sufferers a temperature rise due to the sun light landing on it.
A loaded PV panel (ie connected and providing a current) has the above and the heat from the V x I flowing through the panel.
Hi Steve,
no, it’s just a question of thermodynamics. The joule effect you refer to it is real but when the panel is left unconnected, since the albedo of the panels is highly optimized (and doesn’t change as function of the load), the energy has only one way to go, it has to be converted to heat.
Imagine to put inside a real greenhouse one PV panel with a switch in series to a load resistor which is capable of dissipating to the environment the whole electric energy produced by the panel.
At steady state (after the due time), in both cases (when the switch is open and when it is closed) the temperature inside the greenhouse must be the same, because it depends only by the solar irradiation, the greenhouse thermal insulation and the inner albedo (all of them are unchanging).
So when the switch is open the PV panel must be warmer than when the switch is closed, that because in the first case the resistive load doesn’t dissipate anything, while in the second case it dissipates the whole electric energy produced by the panel.
Have a great day.
Massimo
Steve,
No, when you put a load on the panel you are removing energy in the form of electricity. This energy is then not available to turn into heat. Total energy in (from the sun) must equal total energy out (in electricity and heat).
“At each site, we monitored air temperature continuously for over one year using aspirated temperature probes 2.5 m above the soil surface. Average annual temperature was 22.7 + 0.5 °C in the PV installation, while the nearby desert ecosystem was only 20.3 + 0.5 °C, indicating a PVHI effect. ”
I can only assume that the temperature sensor was placed under the panels, this would reduce radiation to space at night, this effect may have been available to the other two sensors.
.Sensor location was not clear in the article and would likely have a major effect on readings.
Why would you assume that?
Yep. that’s what they said… “This more significant warming under the PVHI than the UHI may be due to heat trapping of re-radiated sensible heat flux under PV arrays at night.”
How about relocating the sensors near the array but without PV obstruction?
For those talking about rain and snow keeping the panels clean, washing debris off, surely the action of rain water/snow running down the panel containing particulates and salt etc would effectively grind the surface to become less transparent?
I have seen cars after a rain storm here in Australia covered in a dusty/sandy coating, and that includes the windscreens.
dpj12—No indeed, solar panels are covered in glass, rain is an effective cleaning process.
When we clean a PV system after about 3 years, we see a 2% to 6% increase in kWH output. the higher numbers usually in areas near large construction. Panels that are mounted flush on a flat roof also see more buildup.
Its not a big problem.
That may be true in Hawaii, but you can’t say that for all locations. Studies have shown that the need for periodic cleaning and replacement of failed panels varies widely by region. Northern climates are by far the worst in that regard.
We had to burn the village to save the village…
My fault – Kleintierzüchterverein defaults to
https://www.google.at/search?client=ms-android-samsung&ei=xkQHWIDDKMWSarmRnOgB&q=+Small+breeders%27+association&oq=+Small+breeders%27+association&gs_l=mobile-gws-serp.3
And thermal power stations have no UHI effect ? How does the amount of UHI compare from the two sources
The whole reason for the existence of these solar fields was to prevent warming. Now we find out they are causing warming.
That’s the irony.
Perhaps you missed the title of the piece?
Hahahaha, hahaha, the climate clowns are so far disconnected from reality they are not even wrong.
Hillary plans to install 500million panels in 4yrs. Now that could give a new Agw temp record for the USA.
Hi John,
“One would expect warming comparable to a dark rooftop or asphalt because of the dark surface of a solar panel. If a lot of the electricity generated by a solar panel is used for lighting or converted into electromagnetic waves in electronic equipment and motors, then the energy is reradiated as something besides heat and escapes the planet and might have an overall cooling effect.”
You are fairly right, but if the albedo with and without the PV panels was unchanged, the final result is just an average almost zero cooling. The electric energy “produced” (or better “converted”) by the PV panels, it mainly has to be converted to heat to escape the planet (I write “mainly” because in case of light production there is the possibility that it left the planet that way). Except for the upwelling light, all the other forms of energy (or work) finally become heat.
So, even leaving the albedo unchanged (which typically is not), the process should lead to little cooling and mostly heat relocation.
In the reality, the albedo should reduce a lot because of the dark surface of the panels, that lead to a total heating effect, partially relocated when the panels are loaded.
Have a great day.
Massimo
The author of a paper on similar research on wind turbines said this:
“the warming effect reported in this study is local and is small compared to the strong background year-to-year land surface temperature changes. Very likely, the wind turbines do not create a net warming of the air and instead only re-distribute the air’s heat near the surface, which is fundamentally different from the large-scale warming effect caused by increasing atmospheric concentrations of greenhouse gases.”
So I would say the same applies to solar panels – its local warming, redistribution, not comparable to large scale warming.
(I will try and find a working link to the research – the one accompanying that quote is bust where I found it)
(This is sort of a hanging curve begging to be hit, so maybe someone’s beat me to it.)
So, climate scientist miss not just the magnitude, but the sign, (plus instead of minus) on a model output that can be verified in real time, but we’re supposed to bankrupt our economy to deal with their forecasts of global temperatures one hundred years from now?
If so, seems like a reason to be a bit skeptical.